class Screen(object):

    @property
    def width(self):
        return self._width
    @width.setter
    def width(self,value):
        self._width = value

    @property
    def height(self):
        return self._height
    @width.setter
    def height(self,value):
        self._height = value

    # 不设置setter方法为只读属性
    @property
    def resolution(self):
        return self.width * self.height





# 测试:
s = Screen()
s.width = 1024
s.height = 768

print('resolution =', s.resolution)


if s.resolution == 786432:
    print('测试通过!')
else:
    print('测试失败!')